`26.` They asked if they was water on Mars.
- S + asked (+object) + if/whether + subject + V
`27.` Aliens much biggers may be than human beings.
- Dịch: Người ngoài hành tinh có thể to lớn hơn nhiều so với con người.
`28. "We can send people to Mars next year." NASA said
`29.` Don't forget to see the Opera House when you are in the Sydney.
`30. `It is difficult to do this exercise.